When road crews inspect a bridge, it works something like this: Workers block a lane of traffic, climb into basket trucks and dangle underneath the roadway, looking for cracks and crumbles.
It’s slow. It’s labor-intensive and potentially dangerous. And it holds up commuters.
But transportation officials in South Carolina may have a better, less-risky option in their hands: drones. They envision a future where unmanned aircraft equipped with cameras buzz around bridges, allowing smaller crews to work more quickly and safely.
South Carolina is one of 17 states experimenting with using remote-controlled drones to rethink how highway departments carry out many of their most routine tasks, according to a survey released last month by the American Association of State Highway and Transportation Officials, or AASHTO.
That means drones could soon be used to reshape processes like inspecting bridges and culverts, surveying land for new roads and assessing damage after disasters. And the national highway department trade group says that while the technology is still young, it could make for safer conditions, lower costs and faster work.
“It’s really evolving fast, but it is still in its early stages,” said AASHTO spokesman Tony Dorsey. “It helps state DOTs to drive decisions based on data.”
The association’s study found that while 17 states had started testing the technology, 16 others were only in the process of “exploring” their use or writing policies on them. The rest haven’t gotten that far.
The S.C. Department of Transportation — a relatively early adopter — hasn’t logged many miles either. It owns a single, $500 drone, and has only flown a handful of test flights, said Stephen Meetze, who’s heading up the drone efforts. It’s a role he picked up in part because he was already flying a drone for fun.
The project, which began about 18 months ago, has had mixed results in the four flights it’s run so far.
On one hand, it’s shown early promise: The South Carolina DOT has used a drone to map out a submerged dam from a perspective workers couldn’t see otherwise, and it was used successfully on a surveying project when the department wanted to make sure a radio tower would have a clear line of sight.
It’s hit a few snags, too, Meetze said. During October’s flooding, he took a video of a crew working on a U.S. Interstate 95 bridge — and then watched helplessly as the battery gave out and the drone plunked into the Black River.
And then there’s the regulatory uncertainty. The DOT drone program is in a holding pattern, Meetze said, because the Federal Aviation Administration’s rules have proven difficult to make sense of and follow.
The federal regulations overseeing drones are still unfinished, and the process of getting permission to fly one for commercial or government use is detailed and often complicated. Projects are approved case-by-case, so agencies can’t get blanket permission to fly. And drone operators have to undergo training as a pilot and get medical certification before they’re cleared for takeoff.
Meetze said he’s taking classes to be certified to fly, but DOT is waiting for the FAA to loosen its rules about what’s required of drone operators before moving ahead, which could happen in the next few months.
Meantime, that’s kept the state transportation department from even applying for a flight certificate: FAA spokesman Les Dorr said the federal agency hadn’t received an application from the department.
“We’re taking it slow,” Meetze said. “And it would have gone a lot smoother and faster if it wasn’t so early in the ballgame.”
Still, DOT expects to start expanding how it uses drones in South Carolina and who can fly them as early as this summer, said Doug Harper, the agency’s chief information officer. They’ve generated lots of interest in the department, Harper said, but so far, only Meetze has taken one out for a spin.
“Initially, when Stephen started off with this, there was a lot of excitement,” Harper said. The department splits the state into seven districts, he said, and the buzz spread through all of them. “Each one wanted to go out and buy one.”
Once the FAA makes it simpler for projects and pilots to get approved, the department plans to start training more people. And while they’re expected to be used primarily for bridge inspections, the move could open the highway department to a variety of new uses — and potential cost savings.
State transportation departments have looked to drones to survey new routes, a process that can take weeks, Dorsey said. They’ve used them to assess how bad car wrecks are, to inspect culverts under roads, and to see how bad flooding or a washout is without sending human crews into harm’s way. They could also help workers check roadside rock faces for weakness, or fly into tanks that workers can’t go into safely.
“It’s a low-cost aerial surveillance,” said Ed McCormack, a transportation engineering professor at the University of Washington who has studied the technology. “Before, where you might use a boom truck if you were a DOT or hire a helicopter, you can send this drone up, which doesn’t cost much money, relatively speaking.”
And drones could be used for more than just taking pictures and videos, McCormack said. Researchers are attaching more sophisticated sensors to collect better data, and in McCormack’s research in Washington and Norway, he’s looked at using them to drop explosives to trigger avalanches safely.
And while South Carolina’s program hasn’t gotten that far, Meetze said he expects the technology to start spreading quickly across the country — once the rules are easier to get through.
“Word was getting around that DOTs were starting to experiment with them,” Meetze said. “We decided that we’d give it a shot, too.”
Reach Thad Moore at 843-937-5703 or on Twitter @thadmoore.